G Series Based on our late model large case GM, Ford or Mitsubishi housings, the tried-and-true G series of alternators are our best sellers. Reasonably priced and very durable, these units feature solid copper custom rectifiers for great durability. Oversize press fit diodes and premium bearings ensure long life even in hot or abusive conditions. Available in 150, 240 or 270 amp configurations. Installation Notes: This unit comes equipped with a smaller 1.75 inch diamter alternator pulley, and will require a slightly shorter drive belt for proper belt tension.